Montrose boss Paul Hegarty called on his players to accept responsibility for a “poor and inept performance” against Elgin City.
Hegarty said: “I played the same team as beat Forfar two weeks ago. It was the same players and the same tactics, so the players have got to take a look at themselves.
“They took the acclaim, and rightly so for beating Forfar. So they must be prepared to take the blame and responsibility for a poor and inept performance, particularly in the first half.
“From three corners we lost three goals due to poor marking, and overall our defensive performance was abysmal.”
He added: “The two dismissals were the icing on the cake. It means we will have two experienced players banned when we need everyone available.”
The visitors took the lead when Daryl McHardy headed home corners after two minutes and 20 minutes.
On 30 minutes, a McGhee corner fell for Brian Cameron to score on the back post.
Top scorer Gary Fraser was booked for dissent in 36 minutes, and for a lunging tackle on Tom Reilly five minutes later.
Shane Sutherland scored for Elgin on 51 minutes when he converted a Cameron cross.
Calum MacDonald was then red-carded for a last-man foul on Chris McLeish on 56 minutes.
Cameron completed the scoring on 84 minutes, tapping home a Craig Gunn cutback.